Electric animal trainer

ABSTRACT

A radio frequency signal modulated at a predetermined audio frequency is transmitted to a receiver carried by the animal to be trained. The modulated signal is detected, amplified and demodulated, and the resulting audio signal is then amplified by a tuned audio amplifier. A trigger circuit is arranged to accept audio signals resulting from an original modulation percentage greater than a predetermined level and to create a voltage pulse at electrodes arranged to bear against the animal&#39;&#39;s fur. Means are provided for attenuating audio signals which differ from the predetermined audio frequency.

United States Patent 1 Gardner et al.

[ Dec. 11, 1973 1 ELECTRIC ANIMAL TRAINER [75] Inventors: Hugh R.Gardner; Calvin l.

Ricketts, both of Las Cruces, N. Mex.; Wesley L. Joosten, El Paso,

Tex.

[73] Assignee: .leteo Electronic lndustries, lnc., El

Paso, Tex.

[22] Filed: Feb. 1, 1972 [21] Appl. No.: 222,499

[52] US. Cl. 119/29, 231/2 E [51] Int. Cl A01k 15/00 [58] Field ofSearch 119/29, 96, 106;

[56] References Cited UNITED STATES PATENTS 3,589,337 6/1971 Doss 119/293,310,754 3/1967 Stewart 325/118 X 3,372,338 3/1968 Kubota et al.325/364 Primary ExaminerLouis G. Mancene Assistant ExaminerJ. N.Eskovitz Attorney-Paul E. Harris et al.

[57] ABSTRACT A radio frequency signal modulated at a predeterminedaudio frequency is transmitted to a receiver carried by the animal to betrained. The modulated signal is detected, amplified and demodulated,and the resulting audio signal is then amplified by a tuned audioamplifier. A trigger circuit is arranged to accept audio signalsresulting from an original modulation percentage greater than apredetermined level and to create a voltage pulse at electrodes arrangedto bear against the animals fur. Means are provided for attenuatingaudio signals which differ from the predetermined audio frequency.

6 Claims, 2 Drawing Figures I C, D,

M/XER- I.F.V 11F. H K] 3 DETECTOR AMF. AMP

CRYSTAL 22 D2 ELECTRIC ANIMAL TRAINER BACKGROUND OF THE INVENTION 1.Field of the Invention Radio signal actuated animal training apparatus.

2. Description of the Prior Art In the training of animals, particularlydogs, it is frequently necessary to issue commands when the dog isphysically separated from the trainer. However, when the commands arenot obeyed, the physical separation involved usually delays correctionof the dog by the trainer, thereby reducing the effectiveness of thecorrection and extending the required training period. Accordingly,various electronic devices have been proposed to allow the trainer topunish the dog immedil5 ately for disobedience.

Most present training devices arranged for remote actuation employ asmall, hand held transmitter in combination with a receiver carried bythe dog on a collar. Shock electrodes carried by the collar and actuatedby the receiver are arranged to provide a harmless but detectable shockto the dog. Using a device of this type the trainer can administerpunishment immediately upon disobedience by the dog and training timecan be significantly reduced.

Various transmitter and receiver circuits have been proposed for use inanimal training systems. Typical are those shown in the U.S. Pat. Nos.to Cameron, 2,800,104, and to Doss, 3,589,337. One feature common toboth foregoing circuits, and used as well by the balance of known priorart, is a vibrator or relay arranged for actuation upon receipt of thedesired signal from the trainers transmitter. The relay is connected tothe primary of a transformer and generates a pulsating do which is thenstepped-up by the transformer to the required shocking potential.However, several problems are encountered when using such a vibrator orrelay. First, being a mechanical device, the relay is subject to thesevere vibrations resulting from the dogs movements, and can fail inservice. Secondly, the physical size and weight of a relay can addsignificantly to the weight of the dog collar device, thereby limitingits usefulness to larger dogs.

Another problem of prior art devices is the type of signal generationand detection employed. One type of device operates on the principle ofthe presence or absence of an r.f. carrier frequency, with a shockpotential generated whenever the receiver detects a carrier on thepredetermined r.f. frequency. However, the range of usable frequenciesfor this service is strictly limited by the F.C.C. Currently suchservice is permitted in the 27 MHz, or class C" band, which is also usedconcurrently by other services. Accordingly, a signal generated by oneof these other services could activate this type of system and couldresult in the unintended generation of a shocking potential. Similarspurious actuation could also arise from spurious radiations, adjacentchannel interference, or atmospheric conditions.

A second type of prior art device overcomes some of the foregoing signalselection problems. This type of device utilizes a time delay featurewhich inhibits generation of the shock potential until a signal has beenreceived for a predetermined time period, usually a second or two.However, such a device is still susceptible to accidental actuations,since spurious and adjacent channel signals may have a duration greaterthan the designed delay period. And, when a modulated signal is thesystem signal in such devices, the receiver generates the shockingpotential after receipt of any frequency audio tone of sufficientduration, including voice signals and heterodynes.

SUMMARY OF THE INVENTION In the instant invention the foregoingdescribed problems are eliminated. The system is designed to use a radiofrequency signal which is modulated to a high percentage bypredetermined audio frequency. The collar receiver detects, amplifiesand demodulates the signal, and the resulting audio signal is amplifiedand used to directly actuate a step-up transformer connected to shockelectrodes. By eliminating the prior art relay or vibrator, the weightof the collar is reduced and its efficiency and reliability aresignificantly increased. The demodulated audio signal is amplified by atuned amplifier, and a trigger circuit connected to the transformer isarranged to accept only audio signals which result from an originalmodulation percentage above a predetermined level. Means are alsoprovided for attenuating audio signals which differ in frequency fromthe predetermined audio frequency. Thus, while some spurious or adjacentchannel signals may contain some audio components at a high percentageof modulation, and some signals may contain audio at the predeterminedaudio frequency, few if any spurious signals will contain high levels ofmodulation at the predetermined frequency, and the system will not beactuated. The system audio frequency can be selected with reference toanticipated adjacent channel uses so as to further minimize accidentalsystem actuation. Usually it is desirable to select audio frequenciesbelow or at the lower range of the human voice spectrum, for example,200 hz. or below.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 illustrates in block diagram anaudio frequency modulated portable transmitter suitable for use withthis invention.

FIG. 2 represents, partially in block diagram and partially inschematic,the receiver portion of the apparatus of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, thetransmitter portion of this system is shown in block diagram andincludes an audio oscillator 11 arranged to generate a 200 hz. audiosignal. As described above this audio frequency is selected since it isbelow the normal 3003,000 hz. human voice spectrum. Therefore, whentuned to this frequency the audio portion of the receiver will beinsensitive to adjacent or co-channel interference from voice signals.Of course, other audio frequencies could be selected for the system, asdesired.

The output from oscillator 11 on line 12 is amplified by modulator l3and fed on line R4 to r.f. crystal oscillator 15. The modulated r.f.signal from oscillator 15 is fed on line 16 to power amplifier 17 whereit is amplified, after which it is transmitted by antenna 18. Noparticular form or arrangement of this transmitter is required, and anyconventional circuitry may be employed. However, it is necessary thatthe audio and r.f. frequencies of the transmitter be compatible withthose of the receiver, as described below. Also, the transmitter shouldbe capable of being modulated to a modulation percentage sufficient toactuate certain receiver circuits, as described below. Although notshown, it is convenient to make the transmitter operable by a pushbutton and to be constructed with compact and efficient battery poweredsolid state elements.

Referring now to FIG. 2, the receiver portion of this embodiment of thesystem will be described in detail. The front end or r.f. stages of thereceiver are conventional in design and include an antenna 20 leading toa mixer-detector 21. Antenna 20 may be integrally formed with the dogcollar (not shown) in any convenient manner. An oscillator 22 supplies asecond signal to mixer-detector 21 on line 23, and the resultantmodulated r.f. signal is fed on wire 24 to a first LF. amplifier 25,with the output from amplifier 25 being fed on wire 26 to a second [.F.amplifier 27.

The modulated r.f. signal output from I.F. amplifier 27 is coupled bycapacitor C1 to the base of transistor 01. Transistor Q1 acts both as anaudio detector, through diode action at the base, and also acts as anaudio amplifier which is tuned to the audio frequency by the C3-L1parallel resonant circuit in the collector circuit ofOl. A bias for O1is derived by supplying the B+ supply to diodes D2 and D3 in seriesthrough limiting resistor R1. This bias signal is supplied to the baseof ()1 through diodes D1 which is maintained in conduction by thecurrent flow through resistor R2. D1 provides a current path comparableto the base-emitter diode of 01 so that the current through C1 will beapproximately equal on positive and negative portions of the modulatedr.f. cycle. The combined voltage drop across D2 and D3 is approximatelyequal to the combined voltages across D1 and the base-emitter diode of01 so that, in the absence ofa modulated r.f. signal, 01 is operating atcut-off very close to conduction. Capacitor C2 is a relatively highvalued by-pass capacitor used to eliminate fluctuations in the biassignal, and the current path through D] prevents the build up ofanegative charge on C1.

Although transistor Q1 switches on and off at the r.f. rate, theparallel tuned circuit C3-L1 causes the signal at the collector ofOl toapproximate a sine wave at the audio frequency. Naturally, C3 and L1 aretuned to the transmitter modulation frequency, e.g., 200 hz. Thus, 01acts as a tuned audio amplifier and does not amplify audio signals whichdiffer appreciably from 200 hz.

The output of O1 is coupled by capacitor C4 to a voltage dividercomposed of R4 and R5. The values of C4 and R4 are appropriatelyselected to act as a high pass filter, allowing audio frequencies of 200hz. and above to pass, and attenuating frequencies below 200 hz. Thevalue of C4 should be selected to have a relatively small capacitivereactance at 200 hz, with a resulting increasing reactance below 200 hz.Therefore C4 and R4 provide further means for attenuating audiofrequencies below the desired audio frequency.

The audio signal passed through C4 is coupled to the base of transistorQ2 through resistor R4. A second unwanted signal rejection occurs at thebase of Q2 through the action of by-pass capacitor C5. C acts as a lowpass filter that has a high capacitive reactance at 200 hz. and adecreasing reactance at higher frequencies, thereby providing means forattenuating audio signals higher than the desired audio frequency.

Transistor O2 is a PNP transistor which operates as an audio amplifierand is biased just above cutoff by the negative base current flowingthrough resistors R4 and R5. 1f R4 were zero, a very small signal fromC4, representative of perhaps a small percentage of modulation in thesignal at the base of Q1, would be sufficient to force O2 to cutoff.However, by properly selecting the values of R4 and R5, any percentagemodulation level can be set as the minimum signal necessary to cut Q2off. Preferably this circuit should be arranged to require a high levelof modulation, on the order of percent or greater, thereby preventingaccidental actuation of the device by spurious signals.

Transistors Q3, Q4 and Q5 act as a trigger circuit, with O3 and Q5functioning as an emitter coupled multivibrator, and Q4 acting as acurrent multiplier for Q5. R6 and R7 provide the collector load for Q3and Q4, respectively, while the primary of T1 in parallel with C6provide a collector load for Q5. R9 is the common emitter resistor forthe multivibrator circuit.

O3 is an NPN transistor having its base coupled to the collector of Q2through resistor R11, and therefore Q3 will conduct when Q2 conducts andwill be cut off when O2 is cut off. if Q2 and 03 are conducting, thenthe base of O4, and consequently the base of 05 will be held near theemitter voltage of Q5, so that Q5 will be cut off. As the base of O3 ismade less positive, it will begin to conduct less, allowing the bases ofQ4 and O5 to become more positive with respect to the emitter of Q5. AsQ5 begins to conduct, the current flow through R9 will increase, tendingto make the emitter of 03 more positive and further decreasing the baseto emitter voltage on Q3. This causes Q3 to cut off further. When 03begins to cut off a regenerative action takes place causing rapidswitching of O3 and of Q4 and OS. If Q3 were initially cut off and anincreasing base voltage is applied, a similar regenerative action occursthrough R9 and the trigger circuit will switch to its opposite statewith Q3 conducting and Q4 and Q5 cut off.

The rapid switching on and off of Q3 and of Q4 and O5 is controlled bythe switching of 02. Therefore, Q5 will switch at the audio frequency,e.g., 200 Hz., alternately providing a current path thru the primary ofT1 and opening this path. Current thru 05 and its load consisting of theprimary of T1 in parallel with C6 is limited by resistor R8. When O5 isswitched on, current builds up in the primary of T1. Due to theinductance of the primary of T1, the signal at the collector of 05 willapproximate a square wave with a positive pulse superimposed thereon atthe beginning of each positive half cycle. When Q5 cuts off, a verylarge voltage pulse occurs on the secondary of T1. Since the desirablevoltage at the secondary of T1 is approximately 1,000 volts, C6 is usedto prevent higher secondary voltages at T1. Another important functionperformed by C6 is to limit the primary voltage pulse in T1 to a valuebelow the breakdown voltage of transistor Q5. 05 must, of course,withstand this high voltage, and the choice of C6 limits the voltage.

The secondary of T1 may be connected directly to shock electrodes or maybe connected in series with limiting resistor R10, as shown in FIG. 2.It is preferable to use a variable resistor such as R10 so thatdifferent electrode voltages may be selected for different animalsand/or for different training conditions.

In operation the collar carrying the HO. 2 apparatus is placed on theanimal and is activated by closing S1. Thereafter, a shock potential isdelivered to the animal whenever a signal is received at the propercarrier frequency which has the proper percentage of modulation of thepreselected audio frequencies. No shock potential results if anunmodulated signal of proper carrier frequency is received or if asignal with proper audio and carrier frequencies but at a low percentageof modulation is received.

Further modifications and alternative embodiments of the apparatus ofthis invention will be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the manner of carrying out the invention. lt is to be understoodthat the form of the invention herewith shown and described is to betaken as the presently preferred embodiment. However, various changesmay be made in these embodiments and equivalent elements or circuits maybe substituted for those illustrated and described herein, parts may bereversed, and certain features of the invention may be utilizedindependently of the use of other features, all as would be apparent toone skilled in the art after having the benefit of this description ofthe invention.

What is claimed is:

1. ln electronic animal training apparatus for use with a radiofrequency transmitter modulated at a predetermined audio frequency, thecombination comprising:

means for detecting and amplifying said audio frequency modulated radiofrequency signal;

means connected to said detecting and amplifying means for demodulatingsaid signal to produce an audio signal at said audio frequency;

means for selectively amplifying said audio signal, said selectiveamplifying means including means for inhibiting amplification of saidaudio signal when the percentage of audio modulation of said radiofrequency signal is below 70 percent; and,

means for communicating said selectively amplified signal to an animalto be trained, said communicating means including: shock electrodesarranged for contact with said animal; and means for coupling saidselectively amplified audio signal to said shock electrodes.

2. The invention as claimed in claim 1, wherein said selectiveamplifying means includes:

a first filter operably connected to said audio amplifier and arrangedto attenuate signals above said audio frequency; and,

a second filter operably connected to said audio amplifier and arrangedto attenuate signals below said audio frequency.

3. The invention as claim in claim 1 wherein said communicating meansincludes:

10 connecting means includes:

a trigger circuit arranged to switch the current in the primary of saidtransformer upon receipt of said selectively amplified audio signal.

5. In electronic animal training apparatus for use with a radiofrequency transmitter modulated at a predetermined audio frequency, thecombination comprising:

means for detecting and amplifying said audio frequency modulated radiofrequency signal;

means connected to said radio frequency signal detecting and amplifyingmeans for detecting and amplifying said audio frequency signal;

said audio detector-amplifier being tuned to said audio frequency;

said audio detector-amplifier also including means for inhibitingamplification of said audio signal when the percentage of audiomodulation of said radio frequency signal is below percent;

a trigger circuit arranged to produce current pulses upon receipt ofsaid audio signal; and,

means for communicating said current pulses to an animal to be trained.

6. in electronic animal training systems, the combination comprising:

pulses from said trigger circuit.

1. In electronic animal training apparatus for use with a radiofrequency transmitter modulated at a predetermined audio frequency, thecombination comprising: means for detecting and amplifying said audiofrequency modulated radio frequency signal; means connected to saiddetecting and amplifying means for demodulating said signal to producean audio signal at said audio frequency; means for selectivelyamplifying said audio signal, said selective amplifying means includingmeans for inhibiting amplification of said audio signal when thepercentage of audio modulation of said radio frequency signal is below70 percent; and, means for communicating said selectively amplifiedsignal to an animal to be trained, said communicating means including:shock electrodes arranged for contact with said animal; and means forcoupling said selectively amplified audio signal to said shockelectrodes.
 2. The invention as claimed in claim 1, wherein saidselective amplifying means includes: a first filter operably connectedto said audio amplifier and arranged to attenuate signals above saidaudio frequency; and, a second filter operably connected to said audioamplifier and arranged to attenuate signals below said audio frequency.3. The invention as claim in claim 1 wherein said communicating meansincludes: a transformer operable at said audio signal frequency; thesecondary of said transformer being connected to said shock electrodes;and, means for connecting said selectively amplified audio signal to theprimary of said transformer.
 4. The invention as claimed in claim 3wherein said connecting means includes: a trigger circuit arranged toswitch the current in the primary of said transformer upon receipt ofsaid selectively amplified audio signal.
 5. In electronic animaltraining apparatus for use with a radio frequency transmitter modulatedat a predetermined audio frequency, the combination comprising: meansfor detecting and amplifying said audio frequency modulated radiofrequency signal; means connected to said radio frequency signaldetecting and amplifying means for detecting and amplifying said audiofrequency signal; said audio detector-amplifier being tuned to saidaudio frequency; said audio detector-amplifier also including means forinhibiting amplification of said audio signal when the percentage ofaudio modulation of said radio frequency signal is below 70 percent; atrigger circuit arranged to produce current pulses upon receipt of saidaudio signal; and, means for communicating said current pulses to ananimal to be trained.
 6. In electronic animal training systems, thecombination comprising: means for transmitting a radio frequency signalmodulated by a preselected audio frequency; means for detecting andamplifying said modulated signal; means for demodulating said modulatedsignal to produce an audio signal; said demodulating means being tunedto said audio frequency; a trigger circuit arranged to provide currentpulses upon receipt of said audio signal; means for inhibiting passageof said audio signal from said demodulating means to said triggercircuit when the audio modulation percentage of said modulated radiofrequency signal is below 70 percent; and, shock electrodes arranged toreceive said current pulses from said trigger circuit.